Certain heterocyclic compounds have been found to be useful starting materials in preparing acetamidine derivatives having pharmacological activity. For example, U.S. Pat. No. 3,917,600 granted Nov. 4, 1975, describes the following compound as a starting material: ##STR2## By a series of complex reactions, this is converted into an acetamidine derivative having antihypertensive activity.
Additional benzofurans as starting material in preparing acetamidine derivatives having pharmacological activity have been desired prior to this invention, so that alternative modes of preparation are available.